Add redis database backend

7 files changed, 322 insertions, 1 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 24bbe7e1d..6836ad6eb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -291,6 +291,25 @@ if(ENABLE_LEVELDB)
 	endif(LEVELDB_LIBRARY AND LEVELDB_INCLUDE_DIR)
 endif(ENABLE_LEVELDB)
 
+set(USE_REDIS 0)
+
+OPTION(ENABLE_REDIS "Enable redis backend" 1)
+
+if(ENABLE_REDIS)
+	find_library(REDIS_LIBRARY hiredis)
+	find_path(REDIS_INCLUDE_DIR hiredis.h PATH_SUFFIXES hiredis)
+	message(STATUS "redis library: ${REDIS_LIBRARY}")
+	message(STATUS "redis headers: ${REDIS_INCLUDE_DIR}")
+	if(REDIS_LIBRARY AND REDIS_INCLUDE_DIR)
+		set(USE_REDIS 1)
+		message(STATUS "redis backend enabled")
+		include_directories(${REDIS_INCLUDE_DIR})
+	else(REDIS_LIBRARY AND REDIS_INCLUDE_DIR)
+		set(USE_REDIS 0)
+		message(STATUS "redis not found!")
+	endif(REDIS_LIBRARY AND REDIS_INCLUDE_DIR)
+endif(ENABLE_REDIS)
+
 configure_file(
 	"${PROJECT_SOURCE_DIR}/cmake_config.h.in"
 	"${PROJECT_BINARY_DIR}/cmake_config.h"
@@ -368,6 +387,7 @@ set(common_SRCS
 	database-dummy.cpp
 	database-leveldb.cpp
 	database-sqlite3.cpp
+	database-redis.cpp
 	player.cpp
 	test.cpp
 	sha1.cpp
@@ -533,6 +553,9 @@ if(BUILD_CLIENT)
 	if (USE_LEVELDB)
 		target_link_libraries(${PROJECT_NAME} ${LEVELDB_LIBRARY})
 	endif(USE_LEVELDB)
+	if (USE_REDIS)
+		target_link_libraries(${PROJECT_NAME} ${REDIS_LIBRARY})
+	endif(USE_REDIS)
 endif(BUILD_CLIENT)
 
 if(BUILD_SERVER)
@@ -550,6 +573,9 @@ if(BUILD_SERVER)
 	if (USE_LEVELDB)
 		target_link_libraries(${PROJECT_NAME}server ${LEVELDB_LIBRARY})
 	endif(USE_LEVELDB)
+	if (USE_REDIS)
+		target_link_libraries(${PROJECT_NAME}server ${REDIS_LIBRARY})
+	endif(USE_REDIS)
 	if(USE_CURL)
 		target_link_libraries(
 			${PROJECT_NAME}server
diff --git a/src/cmake_config.h.in b/src/cmake_config.h.in
index 17d3c2249..906b3e47d 100644
--- a/src/cmake_config.h.in
+++ b/src/cmake_config.h.in
@@ -14,6 +14,7 @@
 #define CMAKE_STATIC_SHAREDIR "@SHAREDIR@"
 #define CMAKE_USE_LEVELDB @USE_LEVELDB@
 #define CMAKE_USE_LUAJIT @USE_LUAJIT@
+#define CMAKE_USE_REDIS @USE_REDIS@
 #define CMAKE_VERSION_MAJOR @VERSION_MAJOR@
 #define CMAKE_VERSION_MINOR @VERSION_MINOR@
 #define CMAKE_VERSION_PATCH @VERSION_PATCH@
diff --git a/src/config.h b/src/config.h
index 1558ebe09..8a9d7d63d 100644
--- a/src/config.h
+++ b/src/config.h
@@ -28,6 +28,10 @@
 	#define USE_LUAJIT 0
 #endif
 
+#ifndef USE_REDIS
+	#define USE_REDIS 0
+#endif
+
 #ifdef USE_CMAKE_CONFIG_H
 	#include "cmake_config.h"
 	#undef PROJECT_NAME
@@ -48,6 +52,8 @@
 	#define USE_LEVELDB CMAKE_USE_LEVELDB
 	#undef USE_LUAJIT
 	#define USE_LUAJIT CMAKE_USE_LUAJIT
+	#undef USE_REDIS
+	#define USE_REDIS CMAKE_USE_REDIS
 	#undef VERSION_MAJOR
 	#define VERSION_MAJOR CMAKE_VERSION_MAJOR
 	#undef VERSION_MINOR
diff --git a/src/database-redis.cpp b/src/database-redis.cpp
new file mode 100644
index 000000000..1d77608f7
--- /dev/null
+++ b/src/database-redis.cpp
@@ -0,0 +1,224 @@
+/*
+Minetest
+Copyright (C) 2014 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "config.h"
+
+#if USE_REDIS
+/*
+	Redis databases
+*/
+
+
+#include "database-redis.h"
+#include <hiredis.h>
+
+#include "map.h"
+#include "mapsector.h"
+#include "mapblock.h"
+#include "serialization.h"
+#include "main.h"
+#include "settings.h"
+#include "log.h"
+
+Database_Redis::Database_Redis(ServerMap *map, std::string savedir)
+{
+	Settings conf;
+	conf.readConfigFile((std::string(savedir) + DIR_DELIM + "world.mt").c_str());
+	std::string tmp;
+	try {
+	tmp = conf.get("redis_address");
+	hash = conf.get("redis_hash");
+	} catch(SettingNotFoundException e) {
+		throw SettingNotFoundException("Set redis_address and redis_hash in world.mt to use the redis backend");
+	}
+	const char *addr = tmp.c_str();
+	int port = conf.exists("redis_port") ? conf.getU16("redis_port") : 6379;
+	ctx = redisConnect(addr, port);
+	if(!ctx)
+		throw FileNotGoodException("Cannot allocate redis context");
+	else if(ctx->err) {
+		std::string err = std::string("Connection error: ") + ctx->errstr;
+		redisFree(ctx);
+		throw FileNotGoodException(err);
+	}
+	srvmap = map;
+}
+
+int Database_Redis::Initialized(void)
+{
+	return 1;
+}
+
+void Database_Redis::beginSave() {
+	redisReply *reply;
+	reply = (redisReply*) redisCommand(ctx, "MULTI");
+	if(!reply)
+		throw FileNotGoodException(std::string("redis command 'MULTI' failed: ") + ctx->errstr);
+	freeReplyObject(reply);
+}
+
+void Database_Redis::endSave() {
+	redisReply *reply;
+	reply = (redisReply*) redisCommand(ctx, "EXEC");
+	if(!reply)
+		throw FileNotGoodException(std::string("redis command 'EXEC' failed: ") + ctx->errstr);
+	freeReplyObject(reply);
+}
+
+void Database_Redis::saveBlock(MapBlock *block)
+{
+	DSTACK(__FUNCTION_NAME);
+	/*
+		Dummy blocks are not written
+	*/
+	if(block->isDummy())
+	{
+		return;
+	}
+
+	// Format used for writing
+	u8 version = SER_FMT_VER_HIGHEST_WRITE;
+	// Get destination
+	v3s16 p3d = block->getPos();
+
+	/*
+		[0] u8 serialization version
+		[1] data
+	*/
+
+	std::ostringstream o(std::ios_base::binary);
+	o.write((char*)&version, 1);
+	// Write basic data
+	block->serialize(o, version, true);
+	// Write block to database
+	std::string tmp1 = o.str();
+	std::string tmp2 = i64tos(getBlockAsInteger(p3d));
+
+	redisReply *reply;
+	reply = (redisReply*) redisCommand(ctx, "HSET %s %s %b", hash.c_str(), tmp2.c_str(), tmp1.c_str(), tmp1.size());
+	if(!reply)
+		throw FileNotGoodException(std::string("redis command 'HSET %s %s %b' failed: ") + ctx->errstr);
+	if(reply->type == REDIS_REPLY_ERROR)
+		throw FileNotGoodException("Failed to store block in Database");
+
+	// We just wrote it to the disk so clear modified flag
+	block->resetModified();
+}
+
+MapBlock* Database_Redis::loadBlock(v3s16 blockpos)
+{
+	v2s16 p2d(blockpos.X, blockpos.Z);
+
+	std::string tmp = i64tos(getBlockAsInteger(blockpos));
+	redisReply *reply;
+	reply = (redisReply*) redisCommand(ctx, "HGET %s %s", hash.c_str(), tmp.c_str());
+	if(!reply)
+		throw FileNotGoodException(std::string("redis command 'HGET %s %s' failed: ") + ctx->errstr);
+
+	if (reply->type == REDIS_REPLY_STRING && reply->len == 0) {
+		freeReplyObject(reply);
+		errorstream << "Blank block data in database (reply->len == 0) ("
+			<< blockpos.X << "," << blockpos.Y << "," << blockpos.Z << ")" << std::endl;
+
+		if (g_settings->getBool("ignore_world_load_errors")) {
+			errorstream << "Ignoring block load error. Duck and cover! "
+				<< "(ignore_world_load_errors)" << std::endl;
+		} else {
+			throw SerializationError("Blank block data in database");
+		}
+		return NULL;
+	}
+
+	if (reply->type == REDIS_REPLY_STRING) {
+		/*
+			Make sure sector is loaded
+		*/
+		MapSector *sector = srvmap->createSector(p2d);
+
+		try {
+			std::istringstream is(std::string(reply->str, reply->len), std::ios_base::binary);
+			freeReplyObject(reply); // std::string copies the memory so we can already do this here
+			u8 version = SER_FMT_VER_INVALID;
+			is.read((char *)&version, 1);
+
+			if (is.fail())
+				throw SerializationError("ServerMap::loadBlock(): Failed"
+					" to read MapBlock version");
+
+			MapBlock *block = NULL;
+			bool created_new = false;
+			block = sector->getBlockNoCreateNoEx(blockpos.Y);
+			if (block == NULL)
+			{
+				block = sector->createBlankBlockNoInsert(blockpos.Y);
+				created_new = true;
+			}
+
+			// Read basic data
+			block->deSerialize(is, version, true);
+
+			// If it's a new block, insert it to the map
+			if (created_new)
+				sector->insertBlock(block);
+
+			// We just loaded it from, so it's up-to-date.
+			block->resetModified();
+		}
+		catch (SerializationError &e)
+		{
+			errorstream << "Invalid block data in database"
+				<< " (" << blockpos.X << "," << blockpos.Y << "," << blockpos.Z
+				<< ") (SerializationError): " << e.what() << std::endl;
+			// TODO: Block should be marked as invalid in memory so that it is
+			// not touched but the game can run
+
+			if (g_settings->getBool("ignore_world_load_errors")) {
+				errorstream << "Ignoring block load error. Duck and cover! "
+					<< "(ignore_world_load_errors)" << std::endl;
+			} else {
+				throw SerializationError("Invalid block data in database");
+			}
+		}
+
+		return srvmap->getBlockNoCreateNoEx(blockpos);  // should not be using this here
+	}
+	return NULL;
+}
+
+void Database_Redis::listAllLoadableBlocks(std::list<v3s16> &dst)
+{
+	redisReply *reply;
+	reply = (redisReply*) redisCommand(ctx, "HKEYS %s", hash.c_str());
+	if(!reply)
+		throw FileNotGoodException(std::string("redis command 'HKEYS %s' failed: ") + ctx->errstr);
+	if(reply->type != REDIS_REPLY_ARRAY)
+		throw FileNotGoodException("Failed to get keys from database");
+	for(size_t i = 0; i < reply->elements; i++)
+	{
+		assert(reply->element[i]->type == REDIS_REPLY_STRING);
+		dst.push_back(getIntegerAsBlock(stoi64(reply->element[i]->str)));
+	}
+	freeReplyObject(reply);
+}
+
+Database_Redis::~Database_Redis()
+{
+	redisFree(ctx);
+}
+#endif
diff --git a/src/database-redis.h b/src/database-redis.h
new file mode 100644
index 000000000..da76775d4
--- /dev/null
+++ b/src/database-redis.h
@@ -0,0 +1,50 @@
+/*
+Minetest
+Copyright (C) 2014 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef DATABASE_REDIS_HEADER
+#define DATABASE_REDIS_HEADER
+
+#include "config.h"
+
+#if USE_REDIS
+
+#include "database.h"
+#include <hiredis.h>
+#include <string>
+
+class ServerMap;
+
+class Database_Redis : public Database
+{
+public:
+	Database_Redis(ServerMap *map, std::string savedir);
+	virtual void beginSave();
+	virtual void endSave();
+	virtual void saveBlock(MapBlock *block);
+	virtual MapBlock* loadBlock(v3s16 blockpos);
+	virtual void listAllLoadableBlocks(std::list<v3s16> &dst);
+	virtual int Initialized(void);
+	~Database_Redis();
+private:
+	ServerMap *srvmap;
+	redisContext *ctx;
+	std::string hash;
+};
+#endif
+#endif
diff --git a/src/main.cpp b/src/main.cpp
index c93af0d77..bb0c3a273 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -84,6 +84,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #ifdef USE_LEVELDB
 #include "database-leveldb.h"
 #endif
+#if USE_REDIS
+#include "database-redis.h"
+#endif
 
 /*
 	Settings.
@@ -1242,7 +1245,7 @@ int main(int argc, char *argv[])
 			}
 			if (!world_mt.exists("backend")) {
 				errorstream << "Please specify your current backend in world.mt file:"
-					<< std::endl << "	backend = {sqlite3|leveldb|dummy}" << std::endl;
+					<< std::endl << "	backend = {sqlite3|leveldb|redis|dummy}" << std::endl;
 				return 1;
 			}
 			std::string backend = world_mt.get("backend");
@@ -1257,6 +1260,10 @@ int main(int argc, char *argv[])
 			else if (migrate_to == "leveldb")
 				new_db = new Database_LevelDB(&(ServerMap&)server.getMap(), world_path);
 			#endif
+			#if USE_REDIS
+			else if (migrate_to == "redis")
+				new_db = new Database_Redis(&(ServerMap&)server.getMap(), world_path);
+			#endif
 			else {
 				errorstream << "Migration to " << migrate_to << " is not supported" << std::endl;
 				return 1;
diff --git a/src/map.cpp b/src/map.cpp
index ec97fedf2..8f612aeac 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -46,6 +46,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #if USE_LEVELDB
 #include "database-leveldb.h"
 #endif
+#if USE_REDIS
+#include "database-redis.h"
+#endif
 
 #define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
@@ -2434,6 +2437,10 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
 		else if (backend == "leveldb")
 			dbase = new Database_LevelDB(this, savedir);
 		#endif
+		#if USE_REDIS
+		else if (backend == "redis")
+			dbase = new Database_Redis(this, savedir);
+		#endif
 		else
 			throw BaseException("Unknown map backend");
 	}